Moisture controller for drycleaning system



' MOISTURE CONTROLLER FOR DRYCLEANING SYSTEM Filed May 21. 1968" 2 Sheets-Sheet 1 O N O 8 [1g INVENTOQ ROBERT A. G ILLESP IE JOWC- M ATTODNEY 8- 1970 I R. A." GILLESPIE ,7

MOISTURE CONTROLLER FOR DRYCLE ANING SYSTEM Filed May 21. 1968 2 Sheets-Sheet 2 I IGZ INVENTOE ROBERT A. G LLESP IE ATTORNEY US. C]. 68-13 10 Claims ABSTRACT OF THE DISCLOSURE A drycleaning system which includes a washer for cleaning fabrics, a filter, conduit means interconnecting the washer and filter and a pump for circulating a volatile organic drycleaning solvent having a drycleaning detergent and water added thereto through the washer and filter. An impedance electrode is connected into the conduit means which is electrically connected to an impedance controller that controls a water supply unit for adding water to the drycleaning system. The impedance electrode means consists of a housing having a single concentric electrode positioned therein and a mounting means for holding said concentric electrode within the housing.

BACKGROUND OF THE INVENTION In the art of drycleaning fabrics, the soiled fabrics are subjected to the action of a volatile organic solvent which is immiscible with water. The present day volatile organic solvents are naphtha, Stoddard solvent, carbon tetrachloride, gasoline, benzene, trichloroethylene, perchloroethylene, and the like, although the Stoddard type and perchloroethylene are the most commonly used. Such solvents are effective for the removal of grease or oil stains as well as dust, dirt, lint and the like which commonly adhere to the grease and oil. It is conventional practice to introduce into the volatile organic solvent in the washer a small portion of an oil soluble dispersing agent or detergent. These are in the form of oil soluble dispersing agents such as oil soluble higher fatty acid soaps or other type of anionic, cationic, or nonionic dispersing agents. However, an oil soluble synthetic organic detergent is preferably employed. These include long chain petroleum sulfonates such as mahogany sulfonates, sulfated fatty alcohol such as lauryl sulfate, long chained sulfyl acetates such as lauryl sulfyl acetate, long chained alkyl sulfosuccinates such as dioctyl sodium sulfyl succinates, higher fatty acid monoglyceride such as mono-olein, higher fatty acid monoglycerides sulfates such as mono-olein, mono sulfates, and the like, the sulfates and sulfonates being used in the form of their salts.

In addition to the dispersing agents and/ or detergents being added to the solventsystems, it is also conventional to introduce into the volatile organic solvent in the Washer a small portion of water. In the presence of such dispersing agents and/or detergents, the water added to the drycleaning volatile organic solvent is a very finely divided colloid dispersed throughout the solvent so as to form what is apparently a homogeneous solution. The amount of water that is added to the volatile organic solvent will vary according to the weight and nature or condition of the fabrics added to the washer and also by United States Patent 3,522,718 Patented Aug. 4, 1970 the relative humidity in the atmosphere and by other factors.

In the drycleaning operation proper, the soiled fabrics will contact the drycleaning solution in the washer or wheel. The fabrics will absorb a certain amount of the water from the drycleaning solution, the amount of absorbed water will depend upon the nature and condition of the fabrics. The remaining moisture in the drycleaning organic solvent solution remains more or less constant during the cleaning operation of that particular batch of clothes. However, when a new batch of clothes or fabrics is introduced into the washer and is contacted with the drycleaning organic solvent solution an additional amount of water is absorbed by the cloth or fabrics. The result is that in the drycleaning operation conducted by most commercial operations the moisture content of the volatile organic solvent solution varies considerably from batch to batch of soiled fabrics and at various stages of use thereof. For the drycleaning of different batches of fabrics, the moisture content drops to a point where it is inadequate to serve its intended purposes and the cleaning results are non-uniform. Additionally, in the drycleaning step proper as noted above, it has been the practice to utilize various concentrations of the detergents therein; During the cleaning of the various batches of fabrics, the volume of the solvent-detergent solution decreases and it has therefore been the practice to replenish it from time to time with more charged solvent.

In order to conserve or reclaim the detergents used within the drycleaning systems, it has been proposed to employ'the so-called two bath system. This procedure involves the use of a second wash or rinse wherein the clothes are agitated within a solvent. In this manner the detergent is clearly removed from the clothing and reclaimed. This procedure has proved to be time consuming and expensive due to the reclaiming operation. Moreover, slight degradation of the fabric has been noted in the two bath system.

In order to obviate these problems, it has been proposed'to employ a conductivity measuring device within the system. This includes an electrode system connected into the system having a pair of spaced apart electrodes within a housing member in the piping wherein the solvent would be passed between the electrodes to measure the resistance of the fluid therebetween. The amount of resistance would be directly proportional to the amount of moisture within the solvent and could be relayed to a controller. The centroller would be automatically open and close a solenoid valve in response to the amount of resistance within the fluid to replenish the water supply. The controllers of these systems are of the Wheatstone bridge type and are not sensitive to the presence of water below about 0.2% by volume. Such a procedure is outlined and claimed in US. Pat. Nos. 2,913,893; 3,101,239 and 3,101,240. However, with the advent of more sophisticated detergent formulations wherein the amount of water added to the solvent systems will range between 0.01 and 0.07% by volume, the above apparatus and procedure has proved to be unworkable. Thus, there has been a long felt need in the industry for a control system to measure the amount of Water added to the system in response to the conductivity of the solvent system to maintain a water content within the solvent system of between 0.01% and 0.07% by volume.

3 BRIEF DESCRIPTION OF THE INVENTION It has been discovered that the water content within a drycleaning volatile organic solvent can be controlled with extreme precision within a range of about 0.01 to about 0.07% by volume. This is brought about by incorporating within the solvent system an impedance electrode having a single electrode concentrically mounted within a housing which measures the conductivity of the fluid within the solvent system. The amount of conductivity is relayed from the electrode to a solid state controller which automatically actuates a Water control system to add water to the system when the Water content of the solvent system becomes below a predetermined volume.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic illustration of a drycleaning system.

FIG. 2 is a cross-sectional view of the impedance electrode of the present invention.

FIG. 3 is a cross-sectional view taken on line 1-1 of FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION In the practice of the present invention, a volatile organic solvent containing a small portion of water and a small amount of detergent is circulated within a drycleaning system. The drycleaning system includes a washer or wheel 1 having the usual door 2 hingedly mounted at 4 therein. The door 2 is provided with the usual window 3 for visual inspection of the washing operation. A button trap 5 is mounted beside the washer 1 and provided with a closure 6 hinged at 7 so that the trap can be cleaned from time to time. A conduit 8 having a union 9 connects the button trap 5 with the inlet portion of a pump 10. The pump 10 is driven by a motor means 11, usually an electrical motor. The motor 11 and pump -10 are mounted on a support number 12. The outlet end of the pump 10 is connected to a conduit 13 having a union 14 therein, which conduit 13 interconnects the inlet 16 of filter with the pump 10. A gauge 18 is mounted within the conduit 13 to visually inspect the pressure within the system.

The filter 15 is provided with the usual cover or closure 17 and supported by legs 17'. The filter 15 functions to remove dirt, lint or other solid materials from the solvent system as is conventional in the art. The outlet 19 of filter 15 is connected to a conduit 20 that is connected into an impedance electrode unit 21. Conduit 22 having a union 23 therein is connected to the exit end of the electrode unit 21 and is connected at its other end to inlet 24 of the washer unit 1. In this manner, the volatile organic solvent can be continuousuly circulated from washer 1 through button trap 5, conduit 8 to pump 10 through conduit '13 to filter 15, through electrode unit 21 and back to the washer 1.

As will be described in further detail hereinafter, the electrode unit 21 is provided with a concentric electrode which functions to sense the conductivity of the fluid material within the solvent system and relays the conductivity through coaxial cable 26 of a fixed length, excess cable is coiled up as noted at 27 to an impedance controller 25. The impedance controller is connected to a source of alternating current as indicated by line 28. The controller 25 is also interconnected to a water supply unit 29 by conventional means 30. The water supply addition unit 29 is of a conventional design and is provided with a source of water supply as indicated at 31 and also a drain unit 34. Line 33 connects the water supply unit to the conduit 8 wherein water is supplied to the drycleaning system. The water supply unit 29 is provided with the usual solenoid valve (not shown) which is activated by the controller 25 to open the line 33 to allow water to be pumped into the drycleaning line 4 8. A meter 32 can be provided within the water supply unit 29 if desired.

Thus, the electrode unit 21 will sense the amount of conductivity within the solvent system which is directly related to the water therein. When the water within the solvent system is reduced to a predetermined amount, the control unit 25 will activate the water supply unit 29 and open the solenoid valve and allow additional water to be pumped into the system. In this manner the water content within the solvent system will be maintained between specifically defined limits.

The impedance electrode unit 21 is provided with a housing member 35 having threads 36 and 37 on its ends as indicated in FIG. 2. The housing 35 is provided with a T-fitting 38 on its upper end which fitting 38 is provided with threads 39 which are complementary with the line 22 within the solvent system. A plug 40 is provided on one side of the T-fitting 38 to provide access to the interior thereof.

The lateral or transverse portion 41 of T-fitting 38 is rigidly connected by screw threads to an adaptor 42 having an opening 43 therein. The adaptor 42 is also provided with lateral flanges 44 which are provided with screw threaded openings so that housing unit 45 can be rigidly attached thereto by threaded members 46. The outer portion of housing unit 45 is provided with a closure cap 47 rigidly attached thereto by threaded members 48. The housing unit 45 is provided with a neck portion 49 which threadedly attaches to a nipple 50 so that the coaxial cable 26 will extend into the housing to be connected thereto.

An insulating means 51 extends through the opening 43 within the adaptor unit 42. The insulating means 51 is provided with a cylindrical portion 52 and an angular portion 53. The angular portion thereof extends through the opening 43. The walls of the opening 43 are complementary with the angular portion 53 of insulating unit 51. Thus, the insulation means 51 not only functions to insulate the housing 35, but also provides a seal therein.

The insulating means 51 is provided with an opening 54 coaxial therethrough which accommodates an elongated support means 55. The elongated member 55 is provided with cylindrical section 56 and an angular section 57. The angular portion 57 is complementary with the angular portion 53 of insulation means 51 and also complementary with the angular portion of the walls of opening 43. A cup-shaped non-conducting spacer 58 having an opening therethrough accommodates the outer portion of support means 55 which portion is provided with threads 59 to accommodate threaded means 60.

The inner portion of supporting means 55 is provided with a threaded opening which accommodates a threaded support means 61, which is connected to the inner electrode 62. The inner electrode 62 is spaced from the housing unit 35 by upper and lower spacer unit 63 and 64. In this instance, there are three spacer units around the electrode 62. The spacer units of course are non-conducting members.

As is apparent from the above description of the electrode unit 21, fluid flowing upwardly therethrough will flow within the tubular member 62 and will also be within the space between housing 35 and electrode 62, which space is indicated at 66.

A source of alternating current is furnished to the electrode 62 by interconnecting one pole of the coaxial cable 26 with the threaded means 59 and the other pole with the ground or housing 35 at one of the screw threaded means 46. In this manner, the conductivity of the fluid between the electrode 62 and housing 35 can be clearly established.

Thus, the amount of conductivity within the fluid medium within the space 66 of electrode unit 21 will be relayed to the control 25 via coaxial cable 26. Impedance control 25 may be defined as a solid state control circuit providing a two-state output determined by the value of the input of the circuit with respect to a predetermined threshold value. The solid state impedance controller 25 can be the detector control circuit defined in US. Pat. No. 3,374,363, the complete and detailed description of which is incorporated herein by reference. Basically, impedance controller unit 25 is responsive to a change in input signal and consists of a source of alternating current supplied to a triggering device having a first input electrode, a second input electrode, and at least a first output electrode therein. A load is connected between the source of alternating current and the first output electrode. A pair of signal input terminals are provided and connected between the first input electrode of the triggering device to one of the signal terminals. Diode means are connected between the second input electrode of the triggering device and the other signal terminals for providing a potential on the second input electrode of the triggering device in excess of the predetermined potential with respect to the potential of the first input terminal of the triggering device when the source polarizes the first output electrode of the triggering device for non-conduction. Thus, a source of alternating current is sent through the coaxial cable 26- to the impedance electrode 21. Since the electrical impedance of the electrode and a given length of coaxial cable are constant, the change in the impedance across the electrode is due to changes in the solvent (i.e., moisture). This is sensed by the controller 25 and at a given setting on the moisture control dial. An impedance across the electrode of less than the dial setting causes the triggering device to conduct on every other alternation of the impressed voltage in a circuit that is external to the voltage that is impressed on the electrode. The resulting pulsating direct current is further modified by other electrical devices to actuate a relay. The circuit is designed in such a way that the relay will not pulse off and on when the circuit is triggered. The one feature of this device is the use of a coaxial cable 26 of a predetermined length to keep the impedance of this sensing circuit constant except for the changes in the solvent and to prevent transit currents from affecting the sensitivity. Another feature is the fact that the solvent impedance is re-evaluated with each alternation of the impressed voltage since the current flow through the trigger device stops on reverse polarity. If the impressed voltage is 60 cycle alternating current, as is commonly used, this re-evaluation takes place every of a second without causing the relay to pulse. These features give very accurate control over solvent impedance which may be used to control the moisture level in the solvent.

In operation, the drycleaning system is first charged with a volatile solvent suitable for drycleaning. Thereafter, a predetermined amount of detergent is added thereto. Then, from about 0.01 to about 0.07% by volume of water is added to the system. The fabrics to be drycleaned are then charged into the washer 1 through door 2. The solvent system is then circulated through the Washer 1 and filter 15, impedance electrode 21 by pump 10. As is well understood, the moisture content within the solvent system will be depleted by the clothing being washed within the washer 1. As the water content within the solvent depletes, the impedance of the solvent system will change and will be sensed by the electrode unit 21. This is brought about by the current flowing between electrode unit 62 and housing 35. The change in impedance is registered to the controller 25 by coaxial cable 26. The controller 25 will then activate the water supply unit 29 and open the solenoid valve and allow water to be charged into conduit 8 of the solvent system by pipe 33. When a sufficient amount of water is added thereto, the water control system is automatically turned off by the controller 25. In this manner, a close tolerance of water content is maintained within the solvent system.

What is claimed is:

1. In a drycleaning system which includes a washer for drycleaning fabrics, a filter, conduit means interconmeeting the Washer and filter and a pump for circulating an organic drycleaning solvent containing a drycleaning detergent and water through said washer and filter, said conduit means containing an impedance electrode means therein; said impedance electrode means electrically connected to an impedance controller that is responsive to the impedance of the fluid within said electrode means to activate a water supply means so that water can be added to the system; the improvement wherein said impedance electrode means comprises a housing unit interconnected into said conduit means; a single electrode positioned concentrically within said housing unit; mounting means for rigidly holding said single electrode means concentrically within said housing unit including a cylindrical member connected to one end of said electrode and extending transversely through an opening in an adaptor rigidly mounted to said housing unit, insulation means positioned between said cylindrical member and said opening wall to insulate and seal said cylindrical member with respect to said housing.

2. The combination as set forth in claim 1, wherein the walls of said opening Within said adaptor diverge upwardly and inwardly with respect to said cylindrical member.

3. The combination as set forth in claim 2, wherein said insulation means is provided with a cylindrical portion and an angular portion which is complementary to the diverging walls of said opening within said adaptor.

4. The combination as set forth in claim 3, wherein said cylindrical member is provided with an angular portion that is complementary to the diverging walls of said opening within said adaptor.

5. The combination as set forth in claim 1, wherein the walls of said opening within said adaptor diverged inwardly and upwardly with respect to said cylindrical member and wherein an insulating means surrounds said cylindrical means and has a portion that is complementary with the diverging Walls of said opening and wherein said cylindrical member is provided with an angular portion that is also complementary to the diverging Walls of said opening within said adaptor.

6. The combination as set forth in claim 1, wherein said impedance controller comprises a source of electrical energy of a reversible polarity, a trigger device having a first input electrode, a second input electrode, and at least a first output electrode; a load and means connecting said load between said source of electrical energy and said first output electrode; a pair of single input terminals; means for connecting said first input electrode of said trigger device to one of said signal terminals; and diode means connected between said second input electrode of said triggering device and the other signal terminal for providing a potential on said second input electrode of said trigger device in excess of a predetermined potential with respect to the potential of said first input terminal of said trigger device when said source polarizes said first output electrode of said trigger device for nonconduction.

7. A combination as set forth in claim 6, wherein the walls of said opening through said adaptor diverge in- 1 wardly and upwardly with respect to said cylindrical member.

8. The combination as set forth in claim 7, wherein said insulation means is provided with an angular section that is complementary to the diverging walls of said opening through said adaptor.

9. The combination as set forth in claim 8, wherein said cylindrical member is provided with an angular section that is complementary to the diverging walls of said opening through said adaptor.

10. The combination as set forth in claim 9, wherein the walls of said opening through said adaptor diverge inwardly and upwardly with respect to said cylindrical member and said insulation means is provided with a cylindrical portion and an angular portion which is complementary to the diverging Walls of said opening and said 7 cylindrical member is provided with an angular section 3,013,572 12/1961 Lahti et a1. 137--93 that is complementary to the walls of said opening 3,101,239 8/ 1963 Warren et a1. 68-13 X through said adaptor. 3,374,363 3/1968 Roberts 307-252 References Cited 5 WILLIAM I. PRICE, Primary Examiner UNITED STATES PATENTS 2,913,893 11/1959 Mathews et a1. 68-18 2,940,287 6/1960 Henderson 6813 6818, 207; 13788, 93 

